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Cohan,Personally, I would never let any seed dry out after sowing.... ever! Once the water absorption process is started my understanding is that letting the seed dry out is terminal and will kill the developing embryo. Those plants that take a couple of years to germinate can tolerate it more because it takes that long for the water to break through the outer levels of the seed (i.e getting rid of the germination inhibitors) so the embryo itself is still insulated inside. I never let any of my seed pots dry out, well not deliberately anyway.To others reading this, if my understanding is incorrect then please let me know. I've certainly always thought that once sown seed should never be allowed to dry out, but if that is incorrect then I would very much like to know.Thanks.
Just noticed yesterday that I have a number of newly germinated Lapeirousia oreogena and jacquinii. These were sown in August 2008 and one seed in each pot germinated. Following advice from a friend in the Southern African Bulb group I allowed the pots to fully dry out and kept them at room temp this summer then watered again in late August. This demonstrates that re-drying the ungerminated seed was not detrimental in this case, and this is also the best germination I have ever had of any Lapeirousia species. This also worked for some Massonia which failed to germinate last year, and a Romulea too.I have failed to germinate any Eriospermum and note that the Goldblatt & Manning encyclopedia of Cape bulbs states that eriospermum are not viable for very long.
A further thought. I think we still don't really understand the ripening process some seeds go through after they are produced. For example:Hesperantha vaginata (the lovely yellow/chocolate one). My own seed sown the autumn after collection (i.e about 4 months old).2007 - no germination out of several hundred seeds2008 - 100% germination very quickly2009 - no germination yet and I'm not hopeful either.All sowing times & conditions were the same.2007 was a very cold & poor summer and I thought that failure was due to the seed not ripening properly so in 2008 I stored the seed in the house during summer (fairly constant 20C) and germination was superb. In 2009 I left the packeted seed in a cool place again and there was no germination again. I wish I had the time to experiment properly with this.